The present invention relates to an air-input speed regulator for pneumatic tool, and more particularly to a regulator that can be easily turned to achieve the purpose of changing a magnitude of torque force of a pneumatic tool.
To change the magnitude of torque force of a pneumatic tool through control of air intake thereof, a flow controller 2 as shown in FIG. 1 is usually connected to a lower end of a pin-shaped air supply switch 1, as shown in FIG. 2. The flow controller 2 is provided at predetermined positions on a front wall with air holes 21 of different diameters, and at an internal space with a steel ball 22 and a spring 23. When the pin-shaped air supply switch 1 is pushed to move the steel ball 22 downward, air is admitted into an air passage of the pneumatic tool via the air holes 21 located at a clearance between the steel ball 22 and a seal ring 24 around a joint of the flow controller 2 and the air supply switch 1, so as to change the flow of air supplied to the tool. In brief, the conventional way of adjusting the torque force of a pneumatic tool is to push and turn the air supply switch 1 to open one of the air holes 21 having different diameters and thereby changes amount and speed of airflow supplied to the tool. The forming of air holes 21 of different diameters disadvantageously complicates the manufacturing of the flow controller 2 to increase the manufacturing cost thereof.
It is therefore a primary object of the present invention to provide an improved air-input speed regulator for pneumatic tool that can be more easily manufactured at reduced cost and be more conveniently operated.
To achieve the above and other objects, the air-input speed regulator for pneumatic tool of the present invention mainly includes an air intake connector having a seat and a tubular portion forward extended from the seat, and a regulating knob rotatably mounted around the connector. Front and rear air holes are axially sequentially formed on the tubular portion of the connector. The regulating knob includes a front tube portion, a front end of which is formed into a plurality of steps gradually lowered in a circumferential direction. By turning the regulating knob, one of the steps is brought to cover the rear air hole on the connector by different extent and therefore changes the amount and speed of air supplied to the pneumatic tool, and thereby regulates the torque force of the tool.
The air intake connector of the air-input speed regulator of the present invention is provided at one side of the seat with an axial channel for receiving a steel ball and a spring therein, and the regulating knob is provided along an inner wall surface with a plurality of circumferentially spaced hollow projections to each correspond to one of the steps. When the regulating knob is turned, one of the hollow projections is brought to engage with the steel ball on the connector and thereby locates the regulating knob in place relative to the connector.